Please do NOT use this VirtualBox Release Candidate on production machines. Entering Release candidate phase means that the feature list is frozen. A VirtualBox Release Candidate is meant for evaluation and testing purposes.

You can download the binaries here.

Please do NOT open bug reports at http://www.virtualbox.org/wiki/Bugtracker but use our VirtualBox Beta/Release Candidate Feedback forum to report any problems with the Release Candidate. Please concentrate on reporting regressions since VirtualBox 4.1.18.

VirtualBox 4.2 will be a new major release. The following major new features were added:

• Improved Windows 8 support, in particular many 3D-related fixes
  
• GUI: VM groups (bug #288)
  
• GUI: expert mode for wizards
  
• GUI: allow to alter some settings during runtime
  
• Support for up to 36 network cards, in combination with an ICH9 chipset configuration (bug #8805)
  
• Resource control: added support for limiting network IO bandwidth; see the manual for more information
  
• Added possibility to start VMs during system boot on Linux, OS X and Solaris; see the manual for more information (bug #950)
  
• Added experimental support for Drag´n´drop from the host to Linux guests. Support for more guests and for guest-to-host is planned. (bug #81)
  
• Added support for Host parallel port passthrough on Windows platform

In addition, the following items were fixed and/or added:

• Mac OS X hosts: sign application and installer to avoid warnings on Mountain Lion
  
• VMM: improved VM context switch performance for Intel CPUs using nested paging
  
• VMM: added support for FlushByASID features of AMD CPUs (Bulldozer and newer)
  
• VMM: fixed unreal mode handling on older CPUs with VT-x (gPXE, Solaris 7/8/9; bug #9941)
  
• VMM: fixed MP tables fixes for I/O APIC interrupt routing relevant for ancient SMP guests (e.g. old OS/2 releases)
  
• VMM: support recent VIA CPUs (bug #10005)
  
• GUI: network operations manager
  
• GUI: allow taking screenshots of the current VM window content
  
• GUI: allow automatically sorting of the VM list
  
• GUI: allow starting of headless VMs from the GUI
  
• GUI: allow reset, shutdown and poweroff from the Manager window
  
• GUI: allow to globally limit the maximum screen resolution for guests
  
• GUI: show the full medium part on hovering the list of recently used ISO images
  
• GUI: do not create additional folders when a new machine has a separator character in its name (bug #6541)
  
• GUI: don´t crash on terminate if the settings dialog is still open (bug #9973)
  
• Snapshots: fixed a crash when restoring an old snapshot when powering off a VM (bug #10491)
  
• Settings: sanitise the name of VM folders and settings file (bug #10549)
  
• Settings: allow to store the iSCSI initiator secret encrypted
  
• E1000: 802.1q VLAN support
  
• Storage: implemented burning of audio CDs in passthrough mode
  
• Storage: implemented support for discarding unused image blocks through TRIM for SATA and IDE and UNMAP for SCSI when using VDI images
  
• Storage: added support for QED images
  
• Storage: added support for QCOW (full support for v1 and readonly support for v2 images)
  
• Storage: added readonly support for VHDX images
  
• Solaris additions: added support for X.org Server 1.11 and 1.12
  
• Windows hosts: no need to recreate host-only adapters after a VirtualBox update
  
• Windows hosts: updated toolchain; make the source code compatible to VC 2010 and enable some security-related compiler options

This list is not complete. This is a first Release Candidate and the code still needs some polishing and not all new features are documented yet. Although we already did a lot of testing and don´t expect critical regressions, please backup your data before trying this Release